Plasmids are extrachromosomal DNA molecules capable of autonomous replication and often contain genes that can be used to alter the characteristics of a cell or an entire organism. Plasmids can be found in a wide range of organisms, including bacteria, plants, and animals, and they are often inherited as part of a cell’s genetic material. The genes contained in plasmids can be used to make proteins, alter the characteristics of a cell or an entire organism, and transfer genes between organisms. Plasmids are one of the primary ways that genes are transferred between organisms.
Characteristics of plasmids
Plasmids are tiny, circular, double-stranded DNA molecules separate from chromosomes in bacteria and other microbes. Plasmids carry genes that are not part of the main chromosome, which allows them to be transferred between bacterial cells. Plasmids typically carry antibiotic resistance genes, which increase the bacteria’s ability to survive in the presence of antibiotics. Although plasmids are found in all bacteria, some bacteria have multiple plasmids, and some even have single chromosome bacteria that carry multiple plasmids.
Functions of plasmids
Plasmids are small genetic molecules essential for bacteria to carry out specific tasks in the environment. They are the “vehicles” that bacteria use to transport genetic material around the cell, and they also control the expression of genes in the cell. The functions of plasmids can be broken down into three main categories:
1) Transport plasmids replicate their genes to copy the plasmid and make more plasmids
2) Control plasmid genes are turned on or off to control the expression of genes.
3) Accessory plasmids provide functions that are not related to the expression of genes, such as manufacturing enzymes or transporting proteins.
What type of genes do plasmids carry?
Plasmids carry Antibiotic Resistance Genes, reporter genes and transgenes. These types of genes may occur naturally or added by scientists in plasmids.
There are 5 types of plasmids:
- Resistance Plasmids
- Virulence Plasmids
- Degradative Plasmids
- Col Plasmids
- Fertility F Plasmids
Resistance Plasmids: It contains such a type of genes that helps the bacterial cell in defending itself from harmful factors such as antibiotics or poison. Some resistance plasmids can transfer themselves through conjugation. The bacterium that carries the resistance plasmid can withstand higher doses of the environmental factor, allowing it to survive and multiply. Some R plasmids also contain genes that enable the bacteria to produce enzymes that break down certain materials in the environment. This enables the bacteria to feed off the materials instead of being restricted to a diet of water and air. R plasmids are passed from bacterium to bacterium by direct cell-to-cell contact, so they are also referred to as “conjugative” plasmids.
Virulence plasmids: Virulence plasmids are genetic elements often found in bacteria and can help bacteria spread faster and travel greater distances. Virulence plasmids are often associated with infections caused by bacteria, such as pneumonia and meningitis. The bacteria that cause these infections can spread to other people through small cuts in the skin or the respiratory tract lining. This can quickly lead to infection of other parts of the body.
Degradative plasmids: They are unique to the Metroid series. Unlike most plasmids, which are substances that can enhance their hosts’ abilities, plasmids associated with Metroid plasmids tend to be more destructive. Degradative plasmids can cause damage to organic and mechanical objects. They can also corrupt mechanical devices, such as machines, turrets, and laser doors.
Col plasmids: It is also known as chromosome plasmids, are small, circular DNA molecules found within cells. They are the only kind of plasmid that can be passed from one cell to another, making them a major means by which bacteria can spread throughout a colony. They are also the only plasmid type that can be seen under a conventional light microscope. Col plasmids are much smaller than other plasmids, typically ranging from 1 to 10kb, and are much simpler in structure, often consisting of a single circular chromosome.
Fertility F Plasmids: They are special genetic material contained in some strains of the D-Series. They are activated when certain conditions are met, often triggered by the moon phases. They cause changes to the host’s body, some of which can be inherited by offspring. The F Plasmids can also be inherited, though this is not common.
Conclusion
Plasmids are small, circular DNA molecules that can be transferred between cells. Plasmids carry genes that enable bacteria to do things their ancestors can’t resist antibiotics and produce fuels like methane. They’re also the primary vehicle to move genes between bacteria strains. Transport plasmids replicate their genes to copy the plasmid and make more plasmids. Control plasmid genes are turned on or off to control the expression of genes. Plasmids carry Antibiotic Resistance Genes, reporter genes and transgenes. These types of genes may occur naturally or added by scientists in plasmids. There are 5 types of plasmids: Resistance Plasmids, Virulence Plasmids, Degradative Plasmids, Col Plasmids, Fertility F Plasmids.